Fabrication of Al-11.2Si Components by Direct Laser Metal Deposition for Automotive Applications

Abstract

Recently, Al-Si alloys samples have been manufactured at lab scale using various additive manufacturing processes, but so far there is no literature available to investigate the feasibility of fabricating Al-Si alloy component for automotive component applications using Direct Laser Metal Deposition (LMD) technique. This paper deals with the practical challenges of building single wall and block deposition (cuboid shapes) of eutectic Al-Si alloy using direct laser metal deposition process for developing automotive applications. Two scanning pattern, hatch pattern and single wall pattern were chosen to study the effect of scanning direction on mechanical properties as well as microstructural evolution. Microstructural investigation of single wall and block deposition using optical and scanning electron microscopy revealed a 99.9% dense component with very fine hypoeutectic microstructure. Tensile test sample extracted from block deposition showed an impressive elongation of 9% with an ultimate tensile strength of 225 MPa and tensile test sample of single wall showed an average elongation of 9.4% with an ultimate tensile strength of 225 MPa. This investigation revealed that direct laser metal deposition could successfully print the eutectic Al-Si alloy bracket on shock tower hood without any distortion or bending.

Characterization of Al-12Si Thin-Wall Properties Fabricated with Laser Direct Energy Deposition

“…The Si peaks are broader, which results in the reduced size of the Si phase in fabricated samples. The results are similar to those already reported by other researchers [18][19][20][21]. However, no phase formation is observed for fabricated samples.…”

“…It can be clearly seen that the dendrites are homogenously distributed along the surface. The growth of the dendrites is not significantly high, which indicates that the material could potentially demonstrate reasonable ductile properties through an inverse relationship, a phenomenon explained by the classical theories of Spear and Gardner [18,19], while some argued that it could be a stepwise dependence on the scale of the dendritic structure. The Secondary Dendrite Arm Spacing (SDAS) is usually correlated with the cooling rate, which is expected to be on the order of 10 3 -10 5 K/s with LMD.…”

Thermoelectric magnetohydrodynamic control of melt pool dynamics and microstructure evolution in additive manufacturing

“…Figure 3b shows the concentration, the white bands being low-concentration regions between successive layers. Figure 4 shows the experimental results from Singh et al [52] where these key features are observed. The predicted features are quite typical of AM processing, and comparing figures 2d and 3b to figure 4, there is a qualitative agreement to experimental observations.…”

Microstructure and mechanical properties of laser metal deposited AlSi10Mg alloys

“…The SDAS can approximately indicate the cooling rate [20,21]. So the cooling rate in this study was calculated by the relationship of , where λ is the SDAS (µm), R is the average cooling rate (K/s) and α = 47, n = 0.33 for eutectic Al–Si alloys [18,22]. The different size of SDAS in fine dendrites zone and coarse dendrites zone is caused by the difference of cooling rate in the molten pool.…”

“…Javidani et al [21] deposited thin-wall parts with the height of about 14 mm with AlSi10Mg. Amrinder Singh et al [22,23] deposited single walls about 20 mm height with Al-11.2Si. Markus et al [34] optimised the energy input of individual tracks and parts with complex shape were built.…”